I'm trying to connect a second HD Omni to my system, but PT won't recognize it. I've successfully connected each of the two Omni's independently, so it's not the units nor the cables. But when I try to connect them both at the same time, whether each are connected to the TB Native box or one is off the expansion port of the other, the second one isn't recognized. Its ring stays amber, and it's not in the hardware set-up. It does, however, keep Pro Tools from playing; I immediately get a CPU/Clocking error. Both are in the Loop Sync chain with a Sync HD.

Any ideas? I've successfully hooked up an additional 192 I/O in the past, so this one has me puzzled.